Nasim nods with self-satisfaction as the worgs withdraw. In a low voice, so as not to be picked up by the worgs' no-doubt-superior hearing, he comments to Humphrey: "Well, that worked exactly as hoped. But perhaps we should consider trying to repair the bridge so we can cross again more easily. The prisoners should be fine as long as no one else with opposable thumbs comes by, but once the orcs are dealt with, best not to leave them too long."

(Incidentally, my internet access will be spotty for roughly the next week. If I don't respond quickly enough at any point, you have my leave to make Nasim do whatever makes sense.)

At this point, the battle is very nearly won. A single successful attack from Nivor will drop the final combatant.

The party can of course pursue the score of orcs that are withdrawing. If they do know another way into the mountain, you might see them again. Otherwise, there is nothing stopping you from continuing your foray into the orc's den.

You know that the ogre leader is out of action, but there were at least a few orcs still deeper in the complex (you heard cursing in orcish when you rescued the prisoners).

Nasim follows up on his comment by trying to assess whether the bridge he just broke can be fixed. If there's still a decent amount of rope at the end after it was severed from the post, I'm assuming it could just be re-tied.

Perhaps an untrained Use Rope check to get a sense whether that's possible? 1d20+4=10